Materials Data on Mg6Sn2Ge by Materials Project
Mg6Sn2Ge is alpha bismuth trifluoride-derived structured and crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded to three equivalent Sn and one Ge atom to form MgSn3Ge tetrahedra that share corners with sixteen MgSn3Ge tetrahedra and edges with six MgSn4 tetrahedra. All Mg–Sn bond lengths are 2.91 Å. The Mg–Ge bond length is 2.81 Å. In the second Mg site, Mg is bonded to one Sn and three equivalent Ge atoms to form a mixture of corner and edge-sharing MgSnGe3 tetrahedra. The Mg–Sn bond length is 2.92 Å. All Mg–Ge bond lengths are 2.88 Å. In the third Mg site, Mg is bonded to four equivalent Sn atoms to form a mixture of corner and edge-sharing MgSn4 tetrahedra. There are three shorter (2.90 Å) and one longer (2.91 Å) Mg–Sn bond lengths. In the fourth Mg site, Mg is bonded to one Sn and three equivalent Ge atoms to form a mixture of corner and edge-sharing MgSnGe3 tetrahedra. The Mg–Sn bond length is 2.92 Å. All Mg–Ge bond lengths are 2.88 Å. Sn is bonded in a body-centered cubic geometry to eight Mg atoms. Ge is bonded in a body-centered cubic geometry to eight Mg atoms.